Correlation between human papillomavirus infection and histopathological diagnosis of women in Northeast Brazil

Cervical carcinoma is the fourth leading cause of death among women worldwide. Epidemiological studies claim that human papillomavirus (HPV) infection is a necessary condition for cervical cancer development. Knowledge of the geographic distribution of HPV is important in guiding the introduction of prophylactic vaccines. This study analyzed the prevalence of HPV infection in cervical samples obtained from women with abnormal cervical histopathological diagnosis in Northeast Brazil. The study included an analysis of 211 women whose diagnosis was confirmed for cervical intraepithelial neoplasia type 1 (CIN-1), cervical intraepithelial neoplasia type 2 (CIN-2), cervical intraepithelial neoplasia type 3 (CIN-3), and cancer. The identification of the HPV genotypes was based on the polymerase chain reaction–restriction fragment length polymorphism technique. A total of 42.7% of the samples showed a single HPV infection, while 57.3% showed multiple infections. The most common genotypes detected were HPV-16, HPV-18, and HPV-31. HPV-16, HPV-31, HPV-35, and HPV-18 were the most common types in CIN-1 with a single infection. HPV-16 and HPV-18 were the most often found in CIN-2 with a single infection. HPV-16, HPV-18, and HPV-31 were the most detected in CIN-3 with a single infection. HPV-16 and HPV-31 were the most frequent in cancer with a single infection. Multiple infection with HPV-16 shows a 2.7 times greater risk of CIN-3 (P = .04). Multiple infections for HPV with HPV-16 and excluding the HPV18/31 types, were associated with CIN-3 (P = .01). The results allowed the detection and genotyping of HPV types circulating in the population studied. These findings must be taken into account when devising vaccination strategies against HPV.     

Prevalence and genotype distribution of cervical human papillomavirus infection: Comparison between pregnant women and non-pregnant controls

Controversies exist on the effect of pregnancy on human papillomavirus (HPV) infection. A cross-sectional section study was conducted to compare the prevalence and genotype distribution of cervical HPV infection between pregnant and non-pregnant women in Hong Kong. Cervical samples were collected from 308 pregnant women and from the same number of age-matched controls recruited from a cervical cancer screening center located at the same hospital. HPV was detected by the polymerase chain reaction, followed by genotype identification by restriction fragment length polymorphism and direct sequencing analyses. The prevalence of HPV for pregnant women was 10.1%, without significant variation with age, gestation, gravidity and parity. The prevalence of HPV for non-pregnant group was 11.4% and did not show significant difference when compared to the pregnant group either by overall or age-stratified subgroup analyses. When the analysis was stratified according to the risk-type of HPV infection, still no significant difference between pregnant and non-pregnant groups was observed (all types: 10.1 vs. 11.4%, P = 0.602; high-risk types: 5.8 vs. 7.8%, P = 0.338; low-risk types: 1.0 vs. 2.9%, P = 0.080; unknown-risk types: 3.2% vs. 1.3%, P = 0.105). The results of this study show no evidence for an influence of pregnancy on HPV prevalence, and a majority of HPV-infected pregnant women had normal cervical cytology. HPV positive results in pregnant women per se should be managed conservatively.     

人乳头瘤病毒致癌机制的研究进展

人乳头瘤病毒 (human papillomavirus, HPV) 是一类小双链DNA病毒,是世界范围内最常见的性传播病原体,其发现是肿瘤病因学研究中的重要成就之一。HPV仅感染人类上皮组织,根据组织亲嗜性的不同,可分为皮肤型和黏膜型;根据HPV致瘤性的高低,又可将黏膜型HPV分为低危型(low risk HPV, LR HPV)和高危型(high risk HPV, HR HPV)。LR HPV主要引起生殖器乳头状瘤和尖锐湿疣等良性病变,而HR HPV则主要引起宫颈不典型增生和宫颈癌。HR HPV可以通过基因整合及对宿主细胞基因组不稳定性、细胞周期、细胞凋亡以及端粒酶活性等产生影响等多种机制导致宫颈上皮的恶性转化。     

Prevalence and genotype distribution of cervical human papillomavirus infection in Macao

Population‐specific epidemiological data on human papillomavirus (HPV) infection are essential for formulating strategies to prevent cervical cancer. The age‐specific prevalence of HPV infection was determined among 1,600 women enrolled for cervical screening in Macao. A U‐shaped age‐specific prevalence curve with a first peak (prevalence rate, 10%) at 20–25 years and a second peak (13%) at 51–55 years was observed. Co‐infections with multiple types were detected in 32.5% of HPV‐positive subjects and without significant variation among different age groups (P = 0.318). The majority (84.6%) of the positive samples harbored high‐ or probable high‐risk HPV types, and these types also exhibited a similar U‐shaped age‐specific prevalence curve. In contrast, low and unknown‐risk HPV types remained at a low prevalence (1.5–2.5%) throughout the age groups between 20 and 50 years, and with a small peak (4.5%) at 51–55 years. HPV 52 was the most common type found in 26.8% of positive samples, followed by HPV 16 (15.5%), HPV 68 (11.4%), HPV 18 and HPV 58 (8.9% each), HPV 54 (8.1%), HPV 53 (7.3%), HPV 39 (6.5%), HPV 33 and HPV 66 (5.7% each). In conclusion, because of the early peak of infection, vaccination and educational campaigns in Macao should start early and target at teenagers. The presence of a second peak containing mainly high‐risk HPV types in older women indicates the need to evaluate the cover of the cervical screening programme for older women. Further study to determine the contribution of HPV 52 in high‐grade cervical neoplasia and invasive cancers in Macao is warranted. J. Med. Virol. 82:1724–1729, 2010. © 2010 Wiley‐Liss, Inc.     

Characterization of human papillomavirus infection in north Taiwan

The detection of human papillomavirus (HPV) is very important for the evaluation of preventative strategies for cervical cancer. The major objective of this study was to characterize the prevalence of different genotypes of HPV in north Taiwan to contribute to the epidemiological knowledge of HPV infections. Papanicolaou (Pap) cervical smears were collected from 10,543 women aged between 14 and 87 years. The polymerase chain reaction (PCR) and DNA array hybridization techniques were used to genotype 51 different HPV strains. HPV was detected in 1,577 women, which gave an overall HPV prevalence rate of 15%. Forty‐eight different genotypes were found in these patients, which included 9.7% that were high‐risk HPV (HR‐HPV) genotypes. The most common types of HR‐HPV in patients, in descending order of frequency, were HPV 52, 16, 58, 56, 39, 51, 18, 68, 31, 33, 59, 45, and 35. HPV 52 was the most frequent type in every age group. The four most common HR‐HPV types were found in 56.6% of the patients infected with HR‐HPV. In cases that were infected with multiple HPV genotypes, 69.2% had at least one HR‐HPV genotype. The rate of infection with HR‐HPV was higher in the younger age groups than the older ones. In conclusion, 48 HPV genotypes were identified from a large study of cervical screening samples and the prevalence of HPV genotypes in different age groups was very diverse. The formulation of a public health strategy for HPV vaccination should take into account the prevalence of various HR‐HPV/LR‐HPV genotypes. J. Med. Virol. 82:1416–1423, 2010. © 2010 Wiley‐Liss, Inc.     

Prevalence of human papillomavirus genotypes and associated cervical squamous intraepithelial lesions in HIV-infected women in Botswana

Human papillomaviruses (HPV) constitute one of the most prevalent sexually transmitted infections and are the etiological agents for invasive cervical cancer, the predominant cancer among women in Botswana. However, the prevalence of HPV genotypes in Botswana has yet to be reported. One hundred thirty‐nine endocervical swabs were taken at baseline from HIV‐1 infected, HSV‐2 seropositive women enrolled in a longitudinal cohort study designed to assess the influence of herpes simplex virus‐2 (HSV‐2) infection on genital tract shedding of HIV‐1. Extracted DNA was evaluated for the presence of low‐risk and high‐risk HPV using the Roche Linear Array. Genotyping identified HPV in 95 of 139 women of which 61/95 were infected with high‐risk HPV and 56/95 with low‐risk HPV. The median number of genotypes was 2 (IQR: 1–4). The most prevalent HPV genotype in HIV‐infected women was HPV 58. Abnormal cervical cytology was detected in 87/127 women and was associated with contemporaneous HPV infection (RR = 1.43, 95% CI: 1.05–1.93; P = 0.02). HPV prevalence was high among HIV‐infected women with infection by multiple genotypes being widespread. The associations attributed to specific oncogenic HPV subtypes and cervical squamous intraepithelial lesions presented here provide critical information to inform future vaccine policy within Botswana. J. Med. Virol. 83:1689–1695, 2011. © 2011 Wiley‐Liss, Inc.     

Identification of a novel human papillomavirus type 16 E1 gene variant with potentially reduced oncogenicity

The human papillomavirus (HPV) 16 genome has been studied extensively, although no study has focused on the E1 gene that is implicated in viral DNA replication. After analyzing the E1 region of HPV 16 genomes in 429 cervical samples, 11.2% were found to contain a 63 nucleotides duplication in this region. Sequence analysis of the E6 and the E7 regions has shown that all samples containing this duplication were related to E6‐G350 variant of the HPV 16 (Chi square test, P = 0.0012). A comparison of cervical lesion severity of the examinees having regular or variant E1 genes has shown that the variant group had a significantly (Fischer's exact test, P = 0.0401) lower percentage of high grade disease cases, suggesting that this particular duplication might reduce the oncogenic potential of HPV 16, and also might clarify the differences of E6‐G350 variant oncogenicity observed in European populations. Albeit, a decreased incidence of high grade cervical lesions can be linked to the prevalence of multiple HPV infection, the additional decrease of those cases with the variant E1 gene versus those without (10.5% and 18.6%, respectively) can only be ascribed to the effect of this particular HPV variant. Further research is needed to clarify the biology of these HPV 16 E1 variants. J. Med. Virol. 80:2134–2140, 2008. © 2008 Wiley‐Liss, Inc.     

The epidemiology of human papillomavirus infection and cervical cancer

Cervical cancer has been recognized as a rare outcome of a common Sexually Transmitted Infection (STI). The etiologic association is restricted to a limited number of viral types of the family of the Human Papillomaviruses (HPVs). The association is causal in nature and under optimal testing systems, HPV DNA can be identified in all specimens of invasive cervical cancer. As a consequence, it has been claimed that HPV infection is a necessary cause of cervical cancer. The evidence is consistent worldwide and implies both the Squamous Cell Carcinomas (SCC), the adenocarcinomas and the vast majority (i.e. > 95%) of the immediate precursors, namely High Grade Squamous Intraepithelial Lesions (HSIL)/Cervical Intraepithelial Neoplasia 3 (CIN3)/Carcinoma in situ. Co-factors that modify the risk among HPV DNA positive women include the use of oral contraceptives (OC) for five or more years, smoking, high parity (five or more full term pregnancies) and previous exposure to other sexually transmitted diseases such as Chlamydia Trachomatis (CT) and Herpes Simplex Virus type 2 (HSV-2). Women exposed to the Human Immunodeficiency Virus (HIV) are at high risk for HPV infection, HPV DNA persistency and progression of HPV lesions to cervical cancer.     

Prevalence and distribution of cervical human papillomavirus genotypes in women with cytological results from Sichuan province,China

The epidemiologic characteristics of human papillomavirus (HPV) genotypes vary by age, ethnicity, and geographic location, and the available data on HPV epidemiological characteristics with cytology results in Sichuan province are limited. Our research was conducted from June 2016 to July 2017. A total of 10 953 women getting HPV testing were enrolled. Liquid-based cytological and histological results were collected. The overall HPV infection rate was 24.1% in Sichuan province. The prevalence of high-risk HPV (hrHPV) was 19.9%. For hrHPV genotypes, HPV52 (15.5%) was the most prevalent genotype, followed by HPV16 (13.8%), HPV58 (13.3%), HPV51 (8.6%), HPV39 (8.1%), and HPV68 (7.8%). Among all HPV-positive women with a cytology or histology result, HPV16-positive women have the highest cervical intraepithelial neoplasia 1 (CIN1)+ prevalence (11.1%), followed by HPV18 and HPV33; HPV16-positive women also have the highest CIN2+ prevalence (9.3%), followed by HPV58 and HPV18. To date, this is the largest study done in the Sichuan province for HPV prevalence and subtype distribution with normal and abnormal cytological results. The age-specific prevalence in patients at gynecology clinics and other clinics is different. Besides, patients at the same age also have a different hrHPV prevalence and lrHPV prevalence. Our result revealed that in every 10 HPV16-positive women, there is approximately one women with CIN2, CIN3, or cervical cancer. A higher oncogenic potential of HPV58 than that of HPV52 was observed.     

Identification of antigenic differences between the phosphorylated and nonphosphorylated forms of the E7 protein of human papillomavirus type 16

To analyze the antigenic properties of the human papillomavirus type 16 E7 oncoprotein, two monoclonal antibodies, VD6 and IB10, that have different reactivities to the E7 protein were generated. While the VD6 antibody reacted strongly with E7 protein in CaSki cell extracts, the other antibody, IB10, showed much weaker reactivity with E7. This reactivity increased in a dose-dependent manner in the presence of the casein kinase II-specific inhibitor DRB (5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole). Antigenic site estimation and an in vitro phosphorylation assay, using bacterially expressed E7 protein, demonstrated that the weak reactivity of IB10 was related to the phosphorylation status of the E7 protein. Phosphorylation of E7 reduced considerably the reactivity of IB10 but did not affect the reactivity of VD6, which reacts with the N-terminal portion of E7. In immunoprecipitation (IP) assays, IB10 precipitated weakly the E7 protein from CaSki cell extracts. Together, these data suggest that unphosphorylated E7 protein shows distinct antigenic character compared to its phosphorylated form under denaturing conditions; however, under native conditions, the phosphorylated and nonphosphorylated E7 proteins have some antigenic cross-reactivity. J. Med. Virol. 54:129–134, 1998. © 1998 Wiley-Liss,Inc.     

常见HR-HPV各型在子宫颈组织中致癌能力的评估

目的探讨高危型人乳头状瘤病毒(high-risk human papilloma viruses,HR-HPV)各型与子宫颈病变进展的关系。方法对135例诊断结果为45例非子宫颈上皮内瘤变(non-squamous intraepithelial lesions,NSIL)、42例低级别鳞状上皮内病变(low-grade squamous intraepithelial lesions,LSIL)、40例高级别鳞状上皮内病变(high-grade squamous intraepithelial lesions,HSIL)、8例子宫颈癌(squamous cervical cancer,SCC)的子宫颈活检组织蜡块进行HPV及E6/E7 mRNA的检测,分别应用PCR-反向杂交法、支链DNA技术(Quantivirus冷光仪)检测。结果 HPV 16在NSIL、LSIL、HSIL、SCC中感染率依次22.22%、21.43%、47.50%、62.50%,呈逐渐递增趋势(P=0.007);单一感染时,HPV 16的E6/E7 mRNA拷贝数依次是1 425.76、3 747.25、1 325.98、86 015.36,与子宫颈病变严重程度具有相关性(P=0.028);多重感染时,HPV 16伴其它HPV感染组在NSIL、LSIL、HSIL、SCC中的E6/E7 mRNA拷贝数呈递增趋势,差异有统计学意义(P=0.040),而其它HPV(不包括HPV 16)感染组表达的mRNA拷贝数与病变严重程度呈负相关性(P=0.044)。结论 HPV 16与子宫颈病变进展的关系最为紧密;在所有HR-HPV中HPV 16的致癌能力最强。     

High prevalence of intermediate-risk human papillomavirus infection in uterine cervices of Kenyan women infected with human immunodeficiency virus

The aim of this study was to investigate an association between certain human papillomavirus (HPV) types and human immunodeficiency virus (HIV) infections. Sexually active females (n = 487; 19-61 years old) were enrolled in the study. Subjects underwent Pap testing and evaluations of HIV and HPV infection status on uterine cervical cell samples. HPV genotyping was performed using a Kurabo GeneSQUARE DNA microarray test. Overall, 23 HPV genotypes were detected, and the most prevalent HPV genotype was HPV-52, followed by HPV-39, -54, -45, -56, -53, -31, -42, -16, -68, and -51. HPV-30, -53, -54, -61, and -66, which are associated with abnormal cytology, are categorized as intermediate-risk in this study. Detection of both high- and intermediate-risk HPV types was significantly associated with cervical abnormality and HIV infection. Multivariate analysis revealed that some high-risk HPV types (HPV-31, -45, -51, -56, and -59) and most intermediate-risk HPV types were associated with HIV infection, while the high-risk types (HPV-16, -18, -33, -35, -39, -52, -58, and -68) were not. The oncogenic effect of the most malignant HPV types (e.g., HPV-16 and -18) appear to be lower, while that of intermediate-risk types are greater, in areas with a high prevalence of HIV infection.     

Local immunosuppression induced by high viral load of human papillomavirus: characterization of cellular phenotypes producing interleukin‐10 in cervical neoplastic lesions

A specific immune response to human papillomavirus (HPV) in the cervical microenvironment plays a key role in eradicating infection and eliminating mutated cells. However, high‐risk HPVs modulate immune cells to create an immunosuppressive microenvironment, and induce these immune cells to produce interleukin 10 (IL‐10). This production of IL‐10, in conjunction with HPV infection, contributes to the appearance of cervical neoplastic lesions. We sought to characterize the IL‐10‐producing cellular phenotype, and investigate the influence of host and HPV factors upon the induction of an immunosuppressive microenvironment. Immunohistochemical analysis demonstrated an increase in IL‐10 production by keratinocytes, macrophages and Langerhans cells in high‐grade cervical lesions and cervical cancer. This increase was more pronounced in patients older than 30 years, and was also correlated with high viral load, and infection with a single HPV type, particularly high‐risk HPVs. Our results indicate the existence of a highly immunosuppressive microenvironment composed of different IL‐10‐producing cellular phenotypes in cervical cancer samples, and samples classified as high‐grade cervical lesions (cervical intraepithelial neoplasia stages II and III). The immunosuppressive microenvironment that developed for these different cellular phenotypes favours viral persistence and neoplastic progression.     

Sequence variation of human papillomavirus type 16 E7 in preinvasive and invasive cervical neoplasias

Variation in the nucleotide sequence of the HPV 16 E7 gene in preinvasive cervical intra-epitherial neoplasia (CIN) and invasive cervical carcinoma specimens was analyzed. Direct DNA sequencing of PCR-amplified products with primers different from those used for PCR with 5-end labeling generated distinct sequence ladders with a low background, even in specimens containing relatively low copy numbers of HPV. Of 14 cervical neoplasias, 11 cases showed sequence diversity from prototype HPV16, and a total of 22 nucleotide exchanges were detected. Nine of these led to single amino acid exchanges: [Thr⁵] to [Lys⁵] in one case and [Asn²⁹] to [Ser²⁹] in eight cases. The [Ser²⁹] E7 was distributed uniformly among invasive carcinomas and precancerous legions, and was also found in a normal cervix. The [Lys⁵] E7 and [Ser²⁹] E7 had transforming potential similar to the prototype E7 assessed by cooperation with the activatedras gene in rat embryo fibroblasts.